Heart wall tension reduction apparatus and method

ABSTRACT

An apparatus for treatment of a failing heart by reducing the wall tension therein. In one embodiment, the apparatus includes a tension member for drawing at least two walls of a heart chamber toward each other. Methods for placing the apparatus on the heart are also provided.

CROSS REFERENCE TO RELATED APPLICATION

This is a division of application Ser. No. 08/933,456 filed Sep. 18,1997 which is a continuation-in-part of U.S. application Ser. No.08/778,277, filed Jan. 2, 1997, entitled "HEART WALL TENSION REDUCTIONAPPARATUS".

FIELD OF THE INVENTION

The present invention pertains to the field of apparatus for treatmentof a failing heart. In particular, the apparatus of the presentinvention is directed toward reducing the wall stress in the failingheart.

BACKGROUND OF THE INVENTION

The syndrome of heart failure is a common course for the progression ofmany forms of heart disease. Heart failure may be considered to be thecondition in which an abnormality of cardiac function is responsible forthe inability of the heart to pump blood at a rate commensurate with therequirements of the metabolizing tissues, or can do so only at anabnormally elevated filling pressure. There are many specific diseaseprocesses that can lead to heart failure with a resulting difference inpathophysiology of the failing heart, such as the dilatation of the leftventricular chamber. Etiologies that can lead to this form of failureinclude idiopathic cardiomyopathy, viral cardiomyopathy, and ischemiccardiomyopathy.

The process of ventricular dilatation is generally the result of chronicvolume overload or specific damage to the myocardium. In a normal heartthat is exposed to long term increased cardiac output requirements, forexample, that of an athlete, there is an adaptive process of slightventricular dilation and muscle myocyte hypertrophy. In this way, theheart fully compensates for the increased cardiac output requirements.With damage to the myocardium or chronic volume overload, however, thereare increased requirements put on the contracting myocardium to such alevel that this compensated state is never achieved and the heartcontinues to dilate.

The basic problem with a large dilated left ventricle is that there is asignificant increase in wall tension and/or stress both during diastolicfilling and during systolic contraction. In a normal heart, theadaptation of muscle hypertrophy (thickening) and ventricular dilatationmaintain a fairly constant wall tension for systolic contraction.However, in a failing heart, the ongoing dilatation is greater than thehypertrophy and the result is a rising wall tension requirement forsystolic contraction. This is felt to be an ongoing insult to the musclemyocyte resulting in further muscle damage. The increase in wall stressis also true for diastolic filling. Additionally, because of the lack ofcardiac output, there is generally a rise in ventricular fillingpressure from several physiologic mechanisms. Moreover, in diastolethere is both a diameter increase and a pressure increase over normal,both contributing to higher wall stress levels. The increase indiastolic wall stress is felt to be the primary contributor to ongoingdilatation of the chamber.

Prior art treatments for heart failure fall into three generallycategories. The first being pharmacological, for example, diuretics. Thesecond being assist systems, for example, pumps. Finally, surgicaltreatments have been experimented with, which are described in moredetail below.

With respect to pharmacological treatments, diuretics have been used toreduce the workload of the heart by reducing blood volume and preload.Clinically, preload is defined in several ways including leftventricular end diastolic pressure (LVEDP), or left ventricular enddiastolic volume (LVEDV). Physiologically, the preferred definition isthe length of stretch of the sarcomere at end diastole. Diuretics reduceextra cellular fluid which builds in congestive heart failure patientsincreasing preload conditions. Nitrates, arteriolar vasodilators,angiotensin converting enzyme inhibitors have been used to treat heartfailure through the reduction of cardiac workload through the reductionof afterload. Afterload may be defined as the tension or stress requiredin the wall of the ventricle during ejection. Inotropes like digoxin arecardiac glycosides and function to increase cardiac output by increasingthe force and speed of cardiac muscle contraction. These drug therapiesoffer some beneficial effects but do not stop the progression of thedisease.

Assist devices include mechanical pumps and electrical stimulators.Mechanical pumps reduce the load on the heart by performing all or partof the pumping function normally done by the heart. Currently,mechanical pumps are used to sustain the patient while a donor heart fortransplantation becomes available for the patient. Electricalstimulation such as bi-ventricular pacing have been investigated for thetreatment of patients with dilated cardiomyopathy.

There are at least three surgical procedures for treatment of heartfailure: 1) heart transplant; 2) dynamic cardiomyoplasty; and 3) theBatista partial left ventriculectomy. Heart transplantation has serious1limitations including restricted availability of organs and adverseeffects of immunosuppressive therapies required following hearttransplantation. Cardiomyoplasty includes wrapping the heart withskeletal muscle and electrically stimulating the muscle to contractsynchronously with the heart in order to help the pumping function ofthe heart. The Batista partial left ventriculectomy includes surgicallyremodeling the left ventricle by removing a segment of the muscularwall. This procedure reduces the diameter of the dilated heart, which inturn reduces the loading of the heart. However, this extremely invasiveprocedure reduces muscle mass of the heart.

SUMMARY OF THE INVENTION

The present invention pertains to a non-pharmacological, passiveapparatus and method for the treatment of a failing heart. The device isconfigured to reduce the tension in the heart wall. It is believed toreverse, stop or slow the disease process of a failing heart as itreduces the energy consumption of the failing heart, decreasesisovolumetric contraction, increases sarcomere shortening duringcontraction and increases isotonic shortening which in turn increasesstroke volume. The device reduces wall tension during diastole andsystole.

In one embodiment, the apparatus includes a tension member for drawingat least two walls of the heart chamber toward each other to reduce theradius or area of the heart chamber in at least one cross sectionalplane. The tension member has anchoring members disposed at oppositeends for engagement with the heart or chamber wall.

In another embodiment, the apparatus includes a compression member fordrawing at least two walls of a heart chamber toward each other. In oneembodiment, the compression member includes a balloon. In anotherembodiment of the apparatus, a frame is provided for supporting thecompression member.

Yet another embodiment of the invention includes a clamp having two endsbiased toward one another for drawing at least two walls of a heartchamber toward each other. The clamp includes at least two ends havingatraumatic anchoring member disposed thereon for engagement with theheart or chamber wall.

In yet another embodiment, a heart wall tension reduction apparatus isprovided which includes a first tension member having two oppositelydisposed ends and first and second elongate anchor members. A secondtension member can be provided. One of the elongate anchors may besubstituted for by two smaller anchors.

In an alternate embodiment of the heart wall tension reductionapparatus, an elongate compression member can be provided. First andsecond elongate lever members preferably extend from opposite ends ofthe compression member. A tension member extends between the first andsecond lever members.

The compression member of the above embodiment can be disposed exteriorto, or internally of the heart. The tension member extends through thechamber or chambers to bias the lever members toward the heart.

In yet another embodiment of a heart wall tension reduction apparatus inaccordance with the present invention, a rigid elongate frame member isprovided. The frame member can extend through one or more chambers ofthe heart. One or more cantilever members can be disposed at oppositeends of the frame member. Each cantilever member includes at least oneatraumatic pad disposed thereon. The atraumatic pads disposed atopposite ends of the frame member can be biased toward each other tocompress the heart chamber.

One method of placing a heart wall tension apparatus or splint on ahuman heart includes the step of extending a hollow needle through atleast one chamber of the heart such that each end of the needle isexternal to the chamber. A flexible leader is connected to a first endof a tension member. A second end of the tension member is connected toan atraumatic pad. The leader is advanced through the needle from oneend of the needle to the other. The leader is further advanced until thesecond end of the tension member is proximate the heart and the firstend of the tension member is external to the heart. A second atraumaticpad is connected to the first end of the tension member such that thefirst and second atraumatic pads engage the heart.

An alternate method of placing the heart wall tension reductionapparatus on the heart includes the step of extending a guide memberthrough at least one chamber of the heart such that each end of theguide member is external to the chamber. A tension member for use inthis method has at least one lumen extending through at least a portionof the member. The guide member is placed in the lumen. The tensionmember is advanced over the guide member such that a first end of thetension member is disposed to one side of and external to the heart anda second end of the tension member is disposed to an opposite side ofand external to the heart. A first atraumatic pad is connected to oneend of the tension member and a second atraumatic pad is connected tothe opposite end of the tension member.

Yet another method of placing a heart wall tension apparatus on a heartincludes the step of extending a needle having a flexible tension memberreleasably connected thereto through at least one chamber of the heartsuch that opposite ends of the tension member are external to thechamber and exposed on opposite sides of the chamber. The needle isremoved from the tension member. Then first and second atraumatic padsare connected to the tension member at opposite ends of the tensionmember.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a transverse cross-section of the left and right ventricles ofa human heart showing the placement of a splint in accordance with thepresent invention;

FIG. 2 is a transverse cross-section of the left and right ventricles ofa human heart showing the placement of a balloon device in accordancewith the present invention;

FIG. 3 is a transverse cross-section of the left and right ventricles ofa human heart showing the placement of an external compression framestructure in accordance with the present invention;

FIG. 4 is a transverse cross-section of the left and right ventricles ofa human heart showing a clamp in accordance with the present invention;

FIG. 5 is a transverse cross-section of the left and right ventricles ofa human heart showing a three tension member version of the splint ofFIG. 1;

FIG. 6 is a transverse cross-section of the left and right ventricles ofa human heart showing a four tension member version of the splint shownin FIG. 1;

FIG. 7 is a vertical cross-sectional view of the left ventricle of ahuman heart showing an alternate version of the splint in accordancewith the present invention;

FIG. 8 is an end of the splint shown in FIG. 7;

FIG. 9 is a vertical cross-sectional view of a chamber of a human heartshowing another alternative embodiment of the splint in accordance withthe present invention;

FIG. 10 is a vertical cross-section of a chamber of a human heartshowing another alternative configuration of splints in accordance withthe present invention;

FIG. 11 is a vertical cross-sectional view of a chamber of a human heartshowing another embodiment of a splint in accordance with the presentinvention;

FIG. 12 is a vertical cross-sectional view of a chamber of a human heartshowing another embodiment of the splint in accordance with the presentinvention;

FIG. 13 is a vertical cross-sectional view of a chamber of a human heartshowing a compression member version of the splint in accordance withthe present invention;

FIG. 14 is a vertical cross-sectional view of a chamber of a human heartshowing another version of the splint shown in FIG. 13;

FIG. 15 is a vertical cross-sectional view of a chamber of a human heartshowing a frame member version of the splint in accordance with thepresent invention;

FIG. 16 is an end view of the splint of FIG. 15;

FIG. 17 is a vertical cross-section of the left ventricle and atrium,the left ventricle having scar tissue;

FIG. 18 is a vertical cross-section of the heart of FIG. 7 showing thesplint of FIG. 1 drawing the scar tissue toward the opposite wall of theleft ventricle;

FIG. 19 is a vertical cross-section of the left ventricle and atrium ofa human heart showing a version of the splint of FIG. 1 having anelongate anchor bar;

FIG. 20 is a side view of an undeployed hinged anchor member;

FIG. 21 is a side view of a deployed hinged anchor member of FIG. 10;

FIG. 22 is a cross-sectional view of an captured ball anchor member;

FIG. 23 is a perspective view of a cross bar anchor member;

FIG. 24 is a vertical cross-sectional view of a chamber of a human heartshowing a needle used for placement of splint in accordance with thepresent invention;

FIG. 25 is a view of the heart and needle of FIG. 24 showing a tensionmember being placed in the heart;

FIG. 26 is a view of the heart shown in FIG. 24 wherein oppositelydisposed anchor pads are being joined by a tension member;

FIG. 27 is a view of the heart of FIG. 24, wherein two oppositelydisposed anchor pads have been joined by two tension members;

FIG. 28 is a view of a tension member having a lumen extendingtherethrough;

FIG. 29 is a view of a tension member having lumens extendingtherethrough;

FIG. 30 is a vertical cross-sectional view of a chamber of the heart andtwo pads, and a needle extending therethrough;

FIG. 31 is a vertical cross-sectional view of a chamber of the heartshowing a guidewire extending therethrough;

FIG. 32 is a view of the heart of FIG. 31, and two pads, and a guidewireextending therethrough;

FIG. 33 is a vertical cross-sectional view of a chamber of the heartshowing a needle connected to a tension member being inserted into thechamber;

FIG. 34 is a vertical cross-sectional view of a chamber of a heartshowing two anchors connected by a tension member;

FIG. 35 is a vertical cross-sectional view of a chamber of the heart,showing a band surrounding the heart;

FIG. 36 is a idealized cylindrical model of a left ventricle of a humanheart;

FIG. 37 is a splinted model of the left ventricle of FIG. 14;

FIG. 38 is a transverse cross-sectional view of FIG. 15 showing variousmodeling parameters;

FIG. 39 is a transverse cross-section of the splinted left ventricle ofFIG. 15 showing a hypothetical force distribution; and

FIG. 40 is a second transverse cross-sectional view of the model leftventricle of FIG. 15 showing a hypothetical force distribution.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein like reference numerals refer tolike elements throughout the several views, FIG. 1 shows a transversecross-section of a left ventricle 10 and a right ventricle 12 of a humanheart 14. Extending through the left ventricle is a splint 16 includinga tension member 18 and oppositely disposed anchors 20. Splint 16 asshown in FIG. 1 has been positioned to draw opposite walls of leftventricle 10 toward each other to reduce the "radius" of the leftventricular cross-section or the cross-sectional area thereof to reduceleft ventricular wall stresses. It should be understood that althoughthe splint 16 and the alternative devices disclosed herein are describedin relation to the left ventricle of a human heart, these devices couldalso be used to reduce the radius or cross-sectional area of the otherchambers of a human heart in transverse or vertical directions, or at anangle between the transverse and vertical.

FIG. 2 discloses an alternate embodiment of the present invention,wherein a balloon 200 is deployed adjacent the left ventricle. The sizeand degree of inflation of the balloon can be varied to reduce theradius or cross-sectional area of left ventricle 10 of heart 14.

FIG. 3 shows yet another alternative embodiment of the present inventiondeployed with respect to left ventricle 10 of human heart 14. Here acompression frame structure 300 is engaged with heart 14 at atraumaticanchor pads 310. A compression member 312 having an atraumatic surface314 presses against a wall of left ventricle 10 to reduce the radius orcross-sectional area thereof.

FIG. 4 is a transverse cross-sectional view of human heart 14 showingyet another embodiment of the present invention. In this case a clamp400 having atraumatic anchor pads 410 biased toward each other is showndisposed on a wall of left ventricle 10. Here the radius orcross-sectional area of left ventricle 10 is reduced by clamping off theportion of the wall between pads 410. Pads 410 can be biased toward eachother and/or can be held together by a locking device.

Each of the various embodiments of the present invention disclosed inFIGS. 1-4 can be made from materials which can remain implanted in thehuman body indefinitely. Such biocompatible materials are well-known tothose skilled in the art of clinical medical devices.

FIG. 5 shows an alternate embodiment of the splint of FIG. 1 referred toin FIG. 5 by the numeral 116. The embodiment 116 shown in FIG. 5includes three tension members 118 as opposed to a single tension member18 as shown in FIG. 1. FIG. 6 shows yet another embodiment of the splint216 having four tension members 218. It is anticipated that in somepatients, the disease process of the failing heart may be so advancedthat three, four or more tension members may be desirable to reduce theheart wall stresses more substantially than possible with a singletension member as shown in FIG. 1.

FIG. 7 is a partial vertical cross-section of human heart 14 showingleft ventricle 10. In FIG. 7, another splint embodiment 316 is shownhaving a tension member 318 extending through left ventricle 10. Onopposite ends of tension member 318 are disposed elongate anchors orpads 320. FIG. 8 is an end view of tension member 318 showing elongateanchor 320.

FIG. 9 shows another embodiment of a splint 416 disposed in a partialvertical cross-section of human heart 14. Splint 416 includes twoelongate anchors or pads 420 similar to those shown in FIGS. 7 and 8. InFIG. 9, however, two tension members 418 extend through left ventricle10 to interconnect anchors 420 on opposite sides of heart 14.

FIG. 10 is a vertical cross section of heart 14 showing left ventricle10. In this case, two splints 16 are disposed through left ventricle 10and vertically spaced from each other to resemble the configuration ofFIG. 9.

FIG. 11 is a vertical cross sectional view of the left ventricle ofheart 14. Two alternate embodiment splints 516 are shown extendingthrough left ventricle 10. Each splint 516 includes two tension members518 interconnecting two anchors or pads 520.

FIG. 12 is yet another vertical cross sectional view of left ventricle10 of heart 14. An alternate embodiment 616 of the splint is shownextending through left ventricle 10. Splint 616 includes an elongateanchor pad 620 and two shorter anchors or pads 621. Splint 616 includestwo tension members 618. Each tension member 618 extends between anchors620 and respective anchors 621.

FIG. 13 is a vertical cross sectional view of left ventricle 10 of heart14. A splint 50 is shown disposed on heart 14. Splint 50 includes acompression member 52 shown extending through left ventricle 10.Opposite ends of compression member 52 are disposed exterior to leftventricle 10. Lever members 54 extend from each end of compressionmember 52 upwardly along the exterior surface of ventricle 10. A tensionmember 56 extends between lever members 54 to bias lever members 54toward heart 14 to compress chamber 10.

Compression member 52 should be substantially rigid, but lever members54 and to some degree compression member 52 should be flexible enough toallow tension member 56 to bias lever members 54 toward heart 14.Alternately, lever members 54 could be hinged to compression member 52such that lever members 54 could pivot about the hinge when biasedtoward heart 14 by tension member 56.

FIG. 14 shows an alternate embodiment 156 of the splint shown in FIG.13. In this case lever members 154 are longer than members 54 ascompression member 152 of splint 150 has been disposed to the exteriorof left ventricle 10.

FIG. 15 is a vertical cross sectional view of left ventricle 10 of heart14. An alternate embodiment 250 of the splint is shown on heart 14. Apreferably relatively rigid frame member 256 extends through ventricle10. Disposed on opposite ends of frame 250 are cantilever member 254.Disposed on cantilever members 254 are atraumatic pads 258. Cantilevermembers 254 can be positioned along frame member 256 such thatatraumatic pads 258 press against heart 14 to compress chamber 10. FIG.16 is an end view of frame member 256 showing cantilever members 254 andpads 258.

It should be understood that each of the embodiments described aboveshould be formed from suitable biocompatible materials known to thoseskilled in the art. The tension members can be formed from flexible orrelatively more rigid material. The compression members and frame membershould be formed from generally rigid material which may flex underload, but generally hold its shape.

FIG. 17 is a partial vertical cross-section of human heart 14 showingleft ventricle 10 and left atrium 22. As shown in FIG. 7, heart 14includes a region of scar tissue 24 associated with an aneurysm orischemia. As shown in FIG. 7, the scar tissue 24 increases the radius orcross-sectional area of left ventricle 10 in the region affected by thescar tissue. Such an increase in the radius or cross-sectional area ofthe left ventricle will result in greater wall stresses on the walls ofthe left ventricle.

FIG. 18 is a vertical cross-sectional view of the heart 14 as shown inFIG. 7, wherein a splint 16 has been placed to draw the scar tissue 24toward an opposite wall of left ventricle 10. As a consequence ofplacing splint 16, the radius or cross-sectional area of the leftventricle affected by the scar tissue 24 is reduced. The reduction ofthis radius or cross-sectional area results in reduction in the wallstress in the left ventricular wall and thus improves heart pumpingefficiency.

FIG. 19 is a vertical cross-sectional view of left ventricle 10 and leftatrium 22 of heart 14 in which a splint 16 has been placed. As shown inFIG. 9, splint 16 includes an alternative anchor 26. The anchor 26 ispreferably an elongate member having a length as shown in FIG. 9substantially greater than its width (not shown). Anchor bar 26 might beused to reduce the radius or cross-sectional area of the left ventriclein an instance where there is generalized enlargement of left ventricle10 such as in idiopathic dilated cardiomyopathy. In such an instance,bar anchor 26 can distribute forces more widely than anchor 20.

FIGS. 20 and 21 are side views of a hinged anchor 28 which could besubstituted for anchors 20 in undeployed and deployed positionsrespectively. Anchor 28 as shown in FIG. 20 includes two legs similar tobar anchor 26. Hinged anchor 28 could include additional legs and thelength of those legs could be varied to distribute the force over thesurface of the heart wall. In addition there could be webbing betweeneach of the legs to give anchor 28 an umbrella-like appearance.Preferably the webbing would be disposed on the surface of the legswhich would be in contact with the heart wall.

FIG. 22 is a cross-sectional view of a capture ball anchor 30. Captureball anchor 30 can be used in place of anchor 20. Capture ball anchor 30includes a disk portion 32 to distribute the force of the anchor on theheart wall, and a recess 34 for receiving a ball 36 affixed to an end oftension member 18. Disk 32 and recess 34 include a side groove whichallows tension member 38 to be passed from an outside edge of disk 32into recess 34. Ball 36 can then be advanced into recess 34 by drawingtension member 18 through an opening 38 in recess 34 opposite disk 32.

FIG. 23 is a perspective view of a cross bar anchor 40. The cross baranchor 40 can be used in place of anchors 20. The anchor 40 preferablyincludes a disk or pad portion 42 having a cross bar 44 extending overan opening 46 in pad 42. Tension member 18 can be extended throughopening 46 and tied to cross bar 42 as shown.

In use, the various embodiments of the present invention are placed inor adjacent the human heart to reduce the radius or cross-section areaof at least one chamber of the heart. This is done to reduce wall stressor tension in the heart or chamber wall to slow, stop or reverse failureof the heart. In the case of the splint 16 shown in FIG. 1, a canula canbe used to pierce both walls of the heart and one end of the splint canbe advanced through the canula from one side of the heart to theopposite side where an anchor can be affixed or deployed. Likewise, ananchor is affixed or deployed at the opposite end of splint 16.

FIG. 24 is a vertical cross-sectional view of a chamber 10 of a heart14. A needle 60 having a stylet inserted therethrough is insertedthrough chamber 10. FIG. 25 shows needle 60 disposed in heart 40 asshown in FIG. 24. In FIG. 25, stylet 62 has been removed. A tensionmember 64 having a flexible leader 66 attached to one end of tensionmember 64, is threaded through needle 60 and an anchor 68.

As shown in FIG. 25, tension member 64 includes a generally elongatecylindrical shaft 70 having two generally cylindrical ends 72. Ends 72preferably have a greater diameter than shaft 70. Also shown in FIG. 25is a perspective view of anchor 68 showing an opening 73 extendingthrough anchor 68. Opening 73 includes a first cylindrically shapedopening 74 extending entirely through anchor 68. The diameter of opening74 is preferably slightly greater than the diameter of end 72 of tensionmember 64. A groove 76 having a width preferably slightly greater thanthat of shaft 70 of tension member 64 extends from opening 74 to agenerally cylindrical opening 78. Generally cylindrical opening 78 has adiameter approximately equal to end 72. Unlike opening 74, however,opening 78 includes a reduced base opening 80 which has a widthapproximately equal to that of groove 76. The width of the opening 80 isalso less than the diameter of end 72 of tension member 64.

It can be appreciated that tension member 64 can be advanced throughopening 74 until shaft 70 is disposed therein. Shaft 70 can be then slidtransversely through groove 76. Tension member 64 can then be advancedfurther through opening 73 until end portion 72 enters opening 78 andseats against base 80.

FIG. 26 shows the view of heart 14 shown in FIG. 25. Needle 60 has beenremoved from heart 14. Tension member 64 has been advanced into chamber10 and anchor 68 connected thereto is engaging the heart wall. Leader 66has been advanced through yet another anchor 68 disposed on the oppositeside of heart 14.

FIG. 27 is a view of heart 14 of FIG. 26. Two tension member 64 havebeen advanced through chamber 10. Each tension member has been seated inrespective opening 78 against respective bases 80 to form a splint in aconfiguration such as that shown in FIG. 9.

It can be appreciated that each of the other tension member splintsconfigurations can be placed on the heart in a similar manner. It canalso be appreciated that anchors 68 could initially be held against theheart and needle 60 advanced through anchors 68 and chamber 10 prior toextending leader 66 through the needle.

FIG. 28 is a perspective view of a tension member 164 in accordance withthe present invention. Tension member 164 is similar to tension member64 described above in that it has an elongate, generally cylindricalshaft 170 and generally cylindrical ends 172. A lumen, however, extendslongitudinally through tension member 164 along axis A.

FIG. 29 is a perspective view of yet another embodiment of the tensionmember 264. Tension member 264, is similar to tension member 164, andincludes an elongate cylindrical shaft 270 and cylindrical ends 272.Lumens 282, however, extend through ends 272 aligned along axis B.

FIG. 30 is a vertical, cross-sectional view of left ventricle 10 ofheart 14. Anchors 68 have been placed on opposite sides of heart 14. Aneedle 160 extends through the lumen of tension member 164, leftventricle 10 and openings 73 in anchors 68. It can be appreciated thattension member 64 can be advanced through anchors 68 and left ventricle10 and be seated within openings 78 as described above with respect totension member 64.

FIG. 31 is a vertical, cross-sectional view of left ventricle 10 ofheart 14. A needle 60 has been advanced through the wall of leftventricle 10 and a guidewire 162 has been advanced through needle 60.

FIG. 32 is the same view of heart 14 as shown in FIG. 32. Needle 60,however, has been removed from heart 14 while guidewire 162 remains inposition. Anchors 68 have been placed on guidewire 162, on oppositesides of left ventricle 10. Tension member 264 has been threaded ontoguidewire 162 through lumens 282. It can be appreciated that asdiscussed above with respect to tension member 164 above, tension member264 can be advanced through left ventricle 10 such that ends 272 oftension member 264 seat in respective openings 78 against base 80.

FIG. 33 is a vertical, cross-sectional view of left ventricle 10 ofheart 14. In FIG. 34, flexible tension member 364 has been connected toa needle 360. Needle 360 is shown being advanced into left ventricle 10through a ventricle wall.

FIG. 34 is the same view of heart 14 as shown in FIG. 33 except thattension member 364 has been advanced entirely through left ventricle 10and anchors 68. Knots 384 have been tied at the ends of tension member364 to prevent the ends of tension member 364 from passing throughopening 73 of anchors 68.

It can be appreciated that the methods described above to advance thetension members through the ventricles can be repeated to advance thedesired number of tension members through the ventricle for a particularconfiguration. The length of the tension members can be determined basedupon the size and condition of the patient's heart. It should also benoted that although the left ventricle has been referred to here forillustrative purposes, that the apparatus and methods of this inventioncan also be used to splint multiple chambers of a patient's heart aswell as the right ventricle or either atrium.

FIG. 35 is a vertical cross-section of left ventricle 10 of heart 14.Disposed about heart 14 is a band 716. Band 716 is shown as being sizedrelative to the heart such that the heart's radius or cross-sectionalarea in a plane parallel to the length of the band is reduced relativeto the radius at that location prior to placement of the band on theheart. The length of the heart perpendicular to the band is alsoincreased. The band may be formed from a continuous ribbon ofelastomeric material or from other biocompatible materials which aresufficiently strong to provide the desired effect of heart radiusreduction and lengthening.

FIG. 36 is a view of a cylinder or idealized heart chamber 48 which isused to illustrate the reduction of wall stress in a heart chamber as aresult of deployment of the splint in accordance with the presentinvention. The model used herein and the calculations related to thismodel are intended merely to illustrate the mechanism by which wallstress is reduced in the heart chamber. No effort is made herein toquantify the actual reduction which would be realized in any particularin vivo application.

FIG. 37 is a view of the idealized heart chamber 48 of FIG. 36 whereinthe chamber has been splinted along its length L such that a "figureeight" cross-section has been formed along the length thereof. It shouldbe noted that the perimeter of the circular transverse cross-section ofthe chamber in FIG. 36 is equal to the perimeter of the figure eighttransverse cross-section of FIG. 37. For purposes of this model,opposite lobes of the figure in cross-section are assumed to be mirrorimages.

FIG. 38 shows various parameters of the FIG. 1 cross-section of thesplinted idealized heart chamber of FIG. 37. Where l is the length ofthe splint between opposite walls of the chamber, R₂ is the radius ofeach lobe, θ is the angle between the two radii of one lobe whichextends to opposite ends of the portion of the splint within chamber 48and h is the height of the triangle formed by the two radii and theportion of the splint within the chamber 48 (R₁ is the radius of thecylinder of FIG. 36). These various parameters are related as follows:

    h=R.sub.2 COS (θ/2)

    l=2R.sub.2 SIN (θ/2)

    R.sub.2 =R.sub.1 π/(2π-θ)

From these relationships, the area of the figure eight cross-section canbe calculated by:

    A.sub.2 =2π(R.sub.2).sup.2 (1-θ/2π)+hl

Where chamber 48 is unsplinted as shown in FIG. 36 A₁, the originalcross-sectional area of the cylinder is equal to A₂ where θ=180°, h=0and l=2R₂. Volume equals A₂ times length L and circumferential walltension equals pressure within the chamber times R₂ times the length Lof the chamber.

Thus, for example, with an original cylindrical radius of fourcentimeters and a pressure within the chamber of 140 mm of mercury, thewall tension T in the walls of the cylinder is 104.4 newtons. When a3.84 cm splint is placed as shown in FIGS. 37 and 38 such that l=3.84cm, the wall tension T is 77.33 newtons.

FIGS. 39 and 40 show a hypothetical distribution of wall tension T andpressure P for the figure eight cross-section. As θ goes from 180° to0°, tension T_(s). in the splint goes from 0 to a 2T load where thechamber walls carry a T load.

In yet another example, assuming that the chamber length L is a constant10 cm, the original radius R₁ is 4 cm, at a 140 mmHg the tension in thewalls is 74.7 N. If a 4.5 cm splint is placed such that l=4.5 cm, thewall tension will then be 52.8 N.

It will be understood that this disclosure, in many respects, is onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, material, and arrangement of parts without exceeding thescope of the invention. Accordingly, the scope of the invention is asdefined in the language of the appended claims.

What is claimed is:
 1. A system for reducing tension in a wall of achamber of a heart, the system comprising:a first member configured tobe positioned transverse the chamber for drawing first portions of thechamber wall toward each other so that the first portions remain in anon-contacting relationship; and a second member configured to bepositioned transverse the chamber and proximate and substantiallyparallel to the first member for drawing second portions of the chamberwall toward each other so that the second portions remain in anon-contacting relationship.
 2. The system of claim 1, furthercomprising an anchor device coupled to the first and second members forfixing the members to the chamber wall.
 3. The system of claim 2,wherein the anchor device includes a first anchor connected to a firstend of each of the first and second members and a second anchorconnected to a second end of each of the first and second members. 4.The system of claim 2, wherein the anchor device includes a separatepair of anchors corresponding to each of the first and second members.5. The system of claim 2, wherein the anchor device includes a firstanchor connected to a first end of the first member, a second anchorconnected to a second end of the first member, a third anchor connectedto a first end of the second member, and a fourth anchor connected to asecond end of the second member.
 6. The system of claim 2, wherein theanchor device includes a first anchor connected to a first end of thefirst member, a second anchor connected to a first end of the secondmember, and a third anchor connected to a second end of each of thefirst and second members.
 7. The system of claim 1, wherein each of thefirst and second members includes a tension member.
 8. The system ofclaim 1, wherein the first member includes a pair of tension members. 9.The system of claim 8, wherein the second member includes a pair oftension members.
 10. The system of claim 1, wherein the first and secondmembers are configured to be positioned transverse the chamber so thatall interior parts of the chamber remain in direct fluid communication.11. An system for reducing tension in a wall of a chamber of a heart,the system comprising:a first member configured to be positionedtransverse the chamber for drawing first portions of the chamber walltoward each other so that all interior parts of the chamber remain indirect fluid communication; and a second member configured to bepositioned transverse the chamber and proximate and substantiallyparallel to the first member for drawing second portions of the chamberwall toward each other so that all interior parts of the chamber remainin direct fluid communication.
 12. The system of claim 11, furthercomprising an anchor device coupled to the first and second members forfixing the members to the chamber wall.
 13. The system of claim 12,wherein the anchor device includes a first anchor connected to a firstend of each of the first and second members and a second anchorconnected to a second end of each of the first and second members. 14.The system of claim 12, wherein the anchor device includes a separatepair of anchors corresponding to each of the first and second members.15. The system of claim 12, wherein the anchor device includes a firstanchor connected to a first end of the first member, a second anchorconnected to a second end of the first member, a third anchor connectedto a first end of the second member, and a fourth anchor connected to asecond end of the second member.
 16. The system of claim 12, wherein theanchor device includes a first anchor connected to a first end of thefirst member, a second anchor connected to a first end of the secondmember, and a third anchor connected to a second end of each of thefirst and second members.
 17. The system of claim 11, wherein each ofthe first and second members includes a tension member.
 18. The systemof claim 11, wherein the first member includes a pair of tensionmembers.
 19. The system of claim 18, wherein the second member includesa pair of tension members.
 20. A system for reducing tension in a wallof a chamber of a heart, the system comprising:a first member configuredto be positioned transverse the chamber for altering a shape of thechamber so that all interior parts of the chamber remain in direct fluidcommunication; and a second member configured to be positionedtransverse the chamber and proximate and substantially parallel to thefirst member for altering the shape of the chamber so that all interiorparts of the chamber remain in direct fluid communication.
 21. Thesystem of claim 20, further comprising an anchor device coupled to thefirst and second members for fixing the members to the chamber wall. 22.The system of claim 21, wherein the anchor device includes a firstanchor connected to a first end of each of the first and second membersand a second anchor connected to a second end of each of the first andsecond members.
 23. The system of claim 21, wherein the anchor deviceincludes a separate pair of anchors corresponding to each of the firstand second members.
 24. The system of claim 21, wherein the anchordevice includes a first anchor connected to a first end of the firstmember, a second anchor connected to a second end of the first member, athird anchor connected to a first end of the second member, and a fourthanchor connected to a second end of the second member.
 25. The system ofclaim 21, wherein the anchor device includes a first anchor connected toa first end of the first member, a second anchor connected to a firstend of the second member, and a third anchor connected to a second endof each of the first and second members.
 26. The system of claim 20,wherein each of the first and second members includes a tension member.27. The system of claim 20, wherein the first member includes a pair oftension members.
 28. The system of claim 27, wherein the second memberincludes a pair of tension members.
 29. A method for placing anapparatus on a heart, the apparatus for reducing tension in a wall of achamber of a heart, the method comprising the steps of:extending ahollow needle through the chamber such that each end of the needle isexternal to the chamber; advancing the apparatus through the needleuntil a first end of the apparatus is external to the chamber; couplingthe first end of the apparatus to a first exterior portion of thechamber; and coupling a second end of the apparatus to a second exteriorportion of the chamber.
 30. The method of claim 29, wherein theadvancing step includes advancing through the needle a tension member ofthe apparatus that is configured to be positioned transverse thechamber.
 31. The method of claim 29, wherein each of the coupling stepsincludes engaging an anchor device with the exterior of the chamber. 32.The method of claim 31, wherein the engaging step includes engaginganchor devices that each include an opening for receiving the apparatus.33. The method of claim 32, wherein the apparatus includes a tensionmember having a first end and a second end and each opening of each ofthe anchor devices has at least a portion having a diametersubstantially equal to a diameter of the first and second ends of thetension member.
 34. The method of claim 29, further comprising the stepof advancing a leader through the needle, the leader being attached tothe apparatus.
 35. The method of claim 29, further comprising the stepof removing the needle from the chamber after the advancing step. 36.The method of claim 29, further comprising the step of positioning thesecond end of the apparatus external to the chamber prior to couplingthe second end of the apparatus to the exterior of the chamber.
 37. Asystem for reducing tension in a wall of a chamber of a heart, thesystem comprising:a first member configured to be positioned transversethe chamber for altering a shape of the chamber so that interiorportions of the wall remain in a non-contacting relationship; and asecond member configured to be positioned transverse the chamber andproximate and substantially parallel to the first member for alteringthe shape of the chamber so that interior portions of the wall remain ina non-contacting relationship.
 38. The system of claim 37, furthercomprising an anchor device coupled to the first and second members forfixing the members to the chamber wall.
 39. The system of claim 38,wherein the anchor device includes a first anchor connected to a firstend of each of the first and second members and a second anchorconnected to a second end of each of the first and second members. 40.The system of claim 38, wherein the anchor device includes a separatepair of anchors corresponding to each of the first and second members.41. The system of claim 38, wherein the anchor device includes a firstanchor connected to a first end of the first member, a second anchorconnected to a second end of the first member, a third anchor connectedto a first end of the second member, and a fourth anchor connected to asecond end of the second member.
 42. The system of claim 38, wherein theanchor device includes a first anchor connected to a first end of thefirst member, a second anchor connected to a first end of the secondmember, and a third anchor connected to a second end of each of thefirst and second members.
 43. The system of claim 37, wherein each ofthe first and second members includes a tension member.
 44. The systemof claim 37, wherein the first member includes a pair of tensionmembers.
 45. The system of claim 44, wherein the second member includesa pair of tension members.